India seeks urgently and expensively to modernise its military. No one in the British delegation will be pressing Indian flesh more eagerly this week than representatives of BAE and Rolls-Royce, who in India are vying for some of the world's biggest weapons contracts. The rest of the Indian scene is not so inviting (and Cameron is wise to refrain from invoking old colonial links, which would slight India's new amour-propre as much as it might gladden British hearts).

The foreign policies of the two countries remain at odds. While Britain sensibly advocates negotiations with the Taliban, India wants its own zone of influence in Afghanistan. India is much closer, politically and commercially, to the US than it is to Britain; the UK government's proposed immigration caps will further deter highly skilled Indians from contributing to the British economy. And British business people seeking fresh openings in India's tightly regulated finance, banking, insurance and retail sectors are likely to be disappointed.

Nevertheless, the coalition government, and its approving media chorus, seems intoxicated by its Rip-Van-Winklish discovery of "Shining India". The old Jewel in the Crown has suddenly mutated into the new El Dorado, and this widespread but unexamined fantasy is already helping the coalition government to dismantle the most principled aspect of Britain's relationship with India. Jo Johnson, the Conservative MP for Orpington, seemed to amplify a growing Tory consensus when, in the Financial Times, he described British aid to India as an "anachronism". Citing India's grand projects and superpower ambitions, Johnson claimed that the country is "no longer a natural aid recipient".

Survival is no less a challenge for many children in Gujarat, one of India's richest states. Poverty and inequality stubbornly persist across India despite spectacular GDP growth, proving the moral nullity of the trickle-down theory, memorably derided by John Kenneth Galbraith as the notion that "if you feed the horse enough oats, some will pass through to the road for the sparrows".

The court was ruling over the acquisition of land by a company that failed to compensate its tribal owners for 23 years. Business people and politicians in India have perpetrated many such blatant, and bigger, injustices in the name of development, forcing many dispossessed people to take up arms in the intensifying Maoist insurgency in central India. As the supreme court observed, development has become a "dreadful and hated word" to millions of Indians.

Dfid – Britain's international development department – has occasionally been complicit in the kind of economic growth that strangulates the poor while making the richest even richer. However, with all its flaws, it is still more conscientious than most of its western peers – especially US aid agencies, which blatantly funnel large portions of "aid" money to American "consultants" while advancing the interests of large American companies. Two-thirds of Dfid's outlay in India is spent on providing health and education services where almost none exist. There is of course ample scope for cutting down wasteful spending and reducing, if not altogether eliminating, corruption. But foreign aid is not an anachronism in a country whose more than 800 million people still live on less than $2 a day: a pitiable budget under assault by double-digit inflation.

It is surely no accident that Cameron's high-powered delegation could not find a place for Andrew Mitchell, the minister in charge of Dfid, which runs the largest single-country programme in India, accounting for nearly 30% of all foreign aid received by the country. Mitchell himself probably put his name on the no-fly-to-India list. "£250m of public money spent annually on nuclear-armed India could be scaled back," he said recently.

Jo Johnson, too, cites India's huge defence budget as evidence that the country can attend to its own development needs. But this defence outlay, which grew by an unprecedented 34% last year and is almost entirely exempt from parliamentary scrutiny or public debate, is an exclusive bonanza for India's alarmingly numerous corrupt politicians, bureaucrats and army officers (whom BAE, with its experience of Saudi Arabia, may be well placed to indulge). Delhi's opulent five-star hotels swarm with lobbyists for Lockheed Martin, Boeing, Dassault and other arms companies. A recent rash of ill-suited and extravagant acquisitions by the Indian government prompted even Sunil Khilnani, a sober political scientist and author of The Idea of India, to warn of a nascent "military-industrial complex" in India.

This is particularly disturbing as the expensive new weapons are likely to be turned against people India claims as its own – and not just in the valley of Kashmir where an anti-India insurgency has consumed more than 80,000 lives, and where Indian security forces have shot dead 17 Muslim protesters, mostly teenagers, in just the past six weeks. The Indian government is also considering deploying the army and air force to suppress the growing Maoist rebellion.

Flying into this gathering storm, the British delegation seems to want little more than safe landing for its Hawk jets and other military hardware. Cameron will no doubt play to the Indian gallery by accusing Pakistan of terrorism while remaining silent about murder and torture in Kashmir. He will tickle the vanity of India's elite by supporting their claims to a permanent seat at the UN security council and other high tables. He may even relax visa rules for Indians. But none of this can compensate for the severing of Britain's old links with India's great mass of ordinary people – or the replacement of Dfid's lifelines to India's poorest with a "new special relationship" that at present promises to do little more than enliven the parties of Delhi's arms dealers.